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Subject:Re: Overcooling Hypothesis--Long
From:Kenneth Wilford
Date:Thu, 27 Dec 2007 14:27:55 -0500

Whoops, I mean 1500 rpms.  Sorry for the confusion.
Kenneth Wilford wrote:
> Yes the injectors are only off above 2000 rpms on deceleration.  Below
> that they come back on.  I have a digitool and have observed this myself
> many times.  So if you can somehow get the rpms down a bit this would
> help (like having the engine at idle by depressing the clutch pedal
> should work).
>
> Ken Wilford
> John 3:16
> www.vanagain.com
>
> Allan Streib wrote:
>> Geza Polony <gezapolony@SBCGLOBAL.NET> writes:
>>
>>
>>> Here's my idea. When you're coasting downhill, you're using the
>>> engine as a brake. This means that above 1500 RPM, with the idle
>>> switch closed, the engine isn't getting any gas, as the ECU has shut
>>> the injectors down. If it isn't getting any gas, it also isn't
>>> producing any heat. The engine is functioning as a brake, but there
>>> isn't any combustion, and so, after a period of 10 minutes or so in
>>> freezing temperatures, the coolant loses temperature, and your gauge
>>> is way off the edge of the scale.
>>>
>>
>> Makes sense.  Not only is there no combustion but you are flushing
>> cold outside air through the cylinders, which has a further cooling
>> effect.
>>
>>
>>> I tested this by going downhill, engine warm, and taking my foot off
>>> the gas to coast. I could see the gauge move colder before my
>>> eyes. Give it a little gas, and the engine warms up. This is kind of
>>> tricky from a driving standpoint, but it works.
>>>
>>
>> Now, repeat the experiment with the clutch in, so the engine is
>> idling, not being overrun.  See if it stays warmer.
>>
>> Allan
>>
>>
>